Insulating and sound proofing material and method of producing same



Patented Jan. 18, 1938 'UNITED STATES PATENT OFFICEy IN SULATING AND SOTERIAL AND SAME Robert Dewey' Snow and Harold UND PROOFING MA- METHOD OFPRODUCING Joseph Hepp,

Bartlesville. Okla., assignors to Phillips Petroleum Company, tion ofDelaware Bartlesville, Okla., a corpora- Application April 18, 1934,Serial No. 721,203 3 Claims. (Cl. 10G-22) 'Ihis invention relates to themanufacture of multicellular heat and sound insulating materials fromthe high molecular weight reaction products of sulfur dioxide andunsaturated compounds, all as more and claimed.

It is well known that cellular material having a large volume percentageof dead gas space in the form of small cells generally has good heatinsulating and sound proofing properties. Such fully hereinafterdescribed Serial No. 599,350, led those described, the most suitable forthe manufacture of our product are the complexes of those oleiinscontaining more than three carbon atoms to the molecule.

Such complexes will absorb considerable quantities of sulfur dioxide andform agelatinous or viscous solution. If the excess sulfur dioxide inthe gelbe'limited to a small amount, and the l gel heated under pressuretill it becomes fluid, a rapid release of the pressure will cause thegel to expand, assuming a. light, fairly uniform, cellular form whosestructure is preserved by cooling. The expanded material may thus beformed by controlled elimination of excess sulfur dioxide. Y

We have also found another way in which expanded, cellular material maybe manufactured from these complexes of sulfur dioxide and unsaturatedcompounds. Virtually all such complexes begin to decompose even belowthe temperatures at which they soften appreciably, regenerating sulfurdioxide and the unsaturated compound. 'I'his decompositionreaction isgen' erally slow below the softening temperatures, but increases rapidlyas the temperature increases. If the solid, resinous material, free fromexcess sulfur dioxide, is heated a short time at a temperature at whichit is Huid, and under pressure suiiicient to prevent the formation of agaseous phase. it ssen accumulates enough deproolng, and heat polymericcompounds -carrying out this process composition products to expand theresin to a cellular form when the pressure is released. Immediatecooling is then provided to prevent further fiow of resin in theintercellular films.

The products produced by either of the above processes are light innweight, but quite strong and resistant to physical damage anddisintegration. From the foregoing, it is evident that they can beproduced either by controlled elimination of excess sulfur the resinousmaterial in sulfur dioxide, or by heating the solid resinous materialunder pressure to a temperature above its softening point, quicklyreleasing the pressure and cooling the expanded product so produced.

The methods of practicing the processes of the present invention areillustrated by the following examples and the accompanying drawing..

Example I One mol. of butene-Z and one and one-quarter mois of SO2 aremixed with a quantity of AgNOs,

LiNOa. NHiNOa or other suitable catalyst. corresponding to 0.01-0.1 percent of the weight of SO2 and olefin, and are allowed to react in apressure vessel. When reaction is complete, the product is warmed to thedesired degree of fluidity and is then forced by pressure through anoriiic into anexpansion chamber where the evaporation of SO2 iscontrolled by pressure. In general the cooling effect due totheevaporation of SO2 is suiiicient and the expansion chamber need not befurther cooled. The same purpose may be accomplished by dissolving thedry, solid resin in SO2 and extruding, and the temperature and partialpressure of-SOa in the expansion chamber may be varied over wide rangesdepending upon the product desired. Apparatus suitable for carrying outthis process is shown in Figure I.

Example II Resin formed by the reaction of SO2 with an unsaturatedcompound is ground or pulverized and the excess SO2 and other volatilematerials are allowed to evaporate. 'I'he resin is then charged to acylinder fitted with a plunger for applying pressure tothe resin andwith steam coils, electric resistance elements or other means ofheating. 'I'he resin is heated under pressure until it is iiuid. Anorifice is opened in the end of the cylinder and the resin is extrudedinto an expansion chamber Where it is quickly cooled in the expandedform. Apparatus suitable for is shownin Figuren.

' I y Example III Resin formed by the reaction o! SO2 with anunsaturated compound is groundor pulverized and is charged to a cylinderfitted with two plungers. Heat and pressure are applied until the resinis iluid. One plunger is suddenly withdrawn and the resin isquicklycooled in the expanded form. That remaining in the cylinder is pushedout with the second plunger. y Apparatus suitable for carrying out thisprocess is shown in Figure III. 4 What we claim and desire to secure byLetters Patent is: 1-5 1. A material suitable for heat and soundinsulation comprising a resinous reaction product of sulfur dioxide andan olefin containing three f orv more carbon atoms in expanded, cellularform,

and essentially non-plastic at atmospheric tem- 20 peratures.

2. A substantially cellular material, light in weight, and suitable forheat and sound insulation, the said material containing small gaspockets surrounded by retaining walls oi a resinous, polymeric compoundformed by the-reaction of sulfur dioxide with 4an olefin of more than fthree carbon atoms to the molecule, and which polymeric compound isessentially non-plastic at atmospheric temperatures. e

3. A substantially cellular material, light in weight, and suitable forheat and sound insulation, thevsaid material containing small gaspockets surrounded by'retaining walls of a resinous, polymeric compoundformed by the reaction of sulfur dioxide with olefins predominantly ofthree or more carbon atoms per molecule and essentially non-plastic atatmospheric temperatures.

ROBERT DEWEY SNOW.

HAROLD JOSEPH HEPP. 20

